Abstract
The rhizome extract of Acorus calamus L. is known to vary according to its region of origin. It is recognised in Indonesia for its value as a botanical insecticide while essential oils derived from Australian native plants are also known to have potential insecticidal properties. In this study, the efficacies of these plant extracts were tested on Plutella xylostella L. This insect pest is known as a major pest of cruciferous vegetables worldwide. The general objective was to investigate the potential effect of Indonesian A. calamus and essential oils from Australian native plants as sources of botanical insecticides. Natural insecticides based on plants represent alternatives to other control methods for insect pests. This is because they generally have less harmful effects to beneficial insects. The characteristics of plant-based insecticides which readily break down into non toxic substances within short periods of time when exposed to sunlight result in less impact on the environment. Likewise, the complex mixtures of the chemical compounds in plant extracts or essential oils can cause difficulty for the insect pest to develop resistance. The chemical compound found in the A. calamus of Indonesian origin is predominantly b-asarone which could be new information for plant classification based on distribution and tetraploid genomic characteristic. Most A. calamus which contains high b-asarone has the tetraploid characteristic. Although the insecticidal efficacy of A. calamus derived using polar solvents, such as ethyl acetate or ethanol is somewhat known plant materials contain both polar organic compounds soluble in methanol, chloroform or ethyl acetate and non polar compounds soluble in benzene or hexane. Thus, to ensure the maximum yield of active compounds derived, in the present study, the extraction process of A. calamus was done by using both polar and non polar solvents i.e. methanol, chloroform, benzene and hexane. The rhizomes of A. calamus utilised were collected from east Java, Indonesia. Extracts were tested for their toxicity, antifeedant effect and, larval development and fecundity effects on P. xylostella. The active ingredient was found to be extractable with equal efficiency using both polar and non-polar solvents which could enable more economic extraction at a commercial level. Along with those extracts, lemon scented tea tree oil from Leptospermum petersonii FM. Bailey and other essential oil formulations based on another tea tree, Melaleuca alternifolia Maiden a Betche were also evaluated. This is believed to be the first report of the efficacy of those essential oils on P. xylostella. Plant essential oils are believed to be safer environmentally and for the user. Their constituents are commonly used as culinary herbs and spices. This fact could bring benefit to their commercialisation as pesticide products because as culinary compounds they may be actually exempted from further toxicology data requirements by the Environmental Protection Authority (EPA) of some countries. The essential oil formulations tested were funga-t-ol; gamma-t-ol; funga-t-ol plus neem oil; and gamma-t-ol plus neem oil. Among them, the funga-t-ol plus neem oil was the most toxic oil against P. xylostella followed by oil of L. petersonii while A. calamus extracts were the least toxic. In laboratory experiments on P. xylostella, it was observed that all of the plant extracts and the essential oils showed strong antifeedant effects and decreased egg production. A. calamus extracts and essential oils were also tested against the egg parasitoid, Trichogramma pretiosum Riley. Few studies have tackled this most important aspect of pest management. A. calamus extracts showed toxicity to the parasitoid. However, L. petersonii oil and all the essential oil formulations showed a lesser negative effect on the parasitoid. To validate the results from the laboratory experiments in semi field conditions, the effects of those oils were assessed under glasshouse conditions. All A. calamus extracts were observed to have negative benefit on the broccoli plant seedlings as phytotoxic symptoms were recorded. In addition it also had a toxic effect on the parasitoid, T. pretiosum. Phytotoxicity effect was also found from L. petersonii oil with a concentration above 2%, however no phytotoxicity effect was found on broccoli seedlings from other essential oil formulations tested. The application of these materials in the field along with other strategies such as timing of application may enhance their efficacy as part of the Integrated Pest Management Program (IPM). The testing done in this study was conducted under laboratory conditions which differ from the field in many respects. Thus there may be a different impact on insect parasitoid as the efficacy of A. calamus decreased overtime in the field under the effect of environmental factors such as sunlight. Positive results were recorded against P. xylostella for the essential oil formulations both in the laboratory and under glasshouse conditions. These therefore, are of agricultural value especially in these days when considerable effort is invested in the search for alternatives to environmentally harmful synthetic pesticides. The combination of toxic effect and antifeedant characteristics of essential oils tested in this study along with insect parasitoid facilitation might have the potential to be developed further towards its implementation in an IPM against P. xylostella.
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Claims 13
Claim · model-written summary
Funga-t-ol plus neem oil was the most toxic oil against P. xylostella.
- Taxon
- broccoli
Brassica oleracea var. italicae2 - Treatment
- funga-t-ol plus neem oile0
- Interactor
- P. xylostellae0pest
- Outcome
- toxic oil against P. xylostellae0
- Direction
- most toxice0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the funga-t-ol plus neem oil was the most toxic oil against P. xylostella”
e2“broccoli plant seedlings”
t1“the funga-t-ol plus neem oil was the most toxic oil against P. xylostella followed by oil of L. petersonii”
Claim · model-written summary
L. petersonii oil ranked after funga-t-ol plus neem oil for pest toxicity.
- Taxon
- broccoliBrassica oleracea var. italicae2
- Treatment
- oil of L. petersoniie0
- Outcome
- toxice0
- Comparator
- funga-t-ol plus neem oilt1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“followed by oil of L. petersonii while A. calamus extracts were the least toxic”
e2“broccoli plant seedlings”
t1“the funga-t-ol plus neem oil was the most toxic oil against P. xylostella followed by oil of L. petersonii”
Claim · model-written summary
A. calamus extracts were least toxic against P. xylostella.
- Taxon
- broccoliBrassica oleracea var. italicae2
- Treatment
- A. calamus extractse0
- Outcome
- least toxice0
- Direction
- least toxice0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A. calamus extracts were the least toxic”
e2“broccoli plant seedlings”
t1“the funga-t-ol plus neem oil was the most toxic oil against P. xylostella followed by oil of L. petersonii”
Claim · model-written summary
Plant extracts and essential oils had strong antifeedant effects on the pest.
- Taxon
- broccoliBrassica oleracea var. italicae2
- Treatment
- plant extracts and the essential oilse0
- Outcome
- antifeedant effectse0
- Direction
- stronge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“all of the plant extracts and the essential oils showed strong antifeedant effects”
e2“broccoli plant seedlings”
t1“the funga-t-ol plus neem oil was the most toxic oil against P. xylostella followed by oil of L. petersonii”
Claim · model-written summary
Plant extracts and essential oils decreased pest egg production.
- Taxon
- broccoliBrassica oleracea var. italicae2
- Treatment
- plant extracts and the essential oilse0
- Outcome
- egg productione0
- Direction
- decreasede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“all of the plant extracts and the essential oils showed strong antifeedant effects and decreased egg production”
e2“broccoli plant seedlings”
t1“the funga-t-ol plus neem oil was the most toxic oil against P. xylostella followed by oil of L. petersonii”
Claim · model-written summary
A. calamus extracts were toxic to the egg parasitoid.
- Taxon
- broccoliBrassica oleracea var. italicae2
- Treatment
- A. calamus extractse0
- Outcome
- toxicity to the parasitoide0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“A. calamus extracts showed toxicity to the parasitoid”
e2“broccoli plant seedlings”
t1“the funga-t-ol plus neem oil was the most toxic oil against P. xylostella followed by oil of L. petersonii”
Claim · model-written summary
L. petersonii oil had less negative effect on the parasitoid.
- Taxon
- broccoliBrassica oleracea var. italicae2
- Treatment
- L. petersonii oile0
- Outcome
- negative effect on the parasitoide0
- Direction
- lessere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“L. petersonii oil and all the essential oil formulations showed a lesser negative effect on the parasitoid”
e2“broccoli plant seedlings”
t1“the funga-t-ol plus neem oil was the most toxic oil against P. xylostella followed by oil of L. petersonii”
Claim · model-written summary
Essential oil formulations had less negative effect on the parasitoid.
- Taxon
- broccoliBrassica oleracea var. italicae2
- Treatment
- essential oil formulationse0
- Outcome
- negative effect on the parasitoide0
- Direction
- lessere0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“all the essential oil formulations showed a lesser negative effect on the parasitoid”
e2“broccoli plant seedlings”
t1“the funga-t-ol plus neem oil was the most toxic oil against P. xylostella followed by oil of L. petersonii”
Claim · model-written summary
A. calamus extracts caused phytotoxic symptoms in broccoli seedlings.
- Taxon
- broccoliBrassica oleracea var. italicae0
- Treatment
- A. calamus extractse0
- Outcome
- phytotoxic symptomse0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“All A. calamus extracts were observed to have negative benefit on the broccoli plant seedlings as phytotoxic symptoms were recorded”
Claim · model-written summary
L. petersonii oil above 2% caused phytotoxicity in broccoli seedlings.
- Taxon
- broccoliBrassica oleracea var. italicae2
- Treatment
- L. petersonii oil with a concentration above 2%e0
- Outcome
- Phytotoxicity effecte0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Phytotoxicity effect was also found from L. petersonii oil with a concentration above 2%”
e2“broccoli plant seedlings”
t1“the funga-t-ol plus neem oil was the most toxic oil against P. xylostella followed by oil of L. petersonii”
Claim · model-written summary
Other essential oil formulations produced no broccoli phytotoxicity.
- Taxon
- broccoliBrassica oleracea var. italicae0
- Treatment
- other essential oil formulationse0
- Outcome
- phytotoxicity effecte0
Not reportedComparatorDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“no phytotoxicity effect was found on broccoli seedlings from other essential oil formulations tested”
Claim · model-written summary
A. calamus efficacy declined over time in the field.
- Taxon
- broccoliBrassica oleracea var. italicae2
- Treatment
- A. calamuse0
- Outcome
- efficacy of A. calamuse0
- Direction
- decreasede0
- Setting
- fielde0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“efficacy of A. calamus decreased overtime in the field under the effect of environmental factors such as sunlight”
e2“broccoli plant seedlings”
t1“the funga-t-ol plus neem oil was the most toxic oil against P. xylostella followed by oil of L. petersonii”
Claim · model-written summary
Essential oil formulations gave positive results against P. xylostella in laboratory and glasshouse tests.
- Taxon
- broccoliBrassica oleracea var. italicae2
- Treatment
- essential oil formulationse0
- Interactor
- P. xylostellae0pest
- Outcome
- Positive resultse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Positive results were recorded against P. xylostella for the essential oil formulations both in the laboratory and under glasshouse conditions”
e2“broccoli plant seedlings”
t1“the funga-t-ol plus neem oil was the most toxic oil against P. xylostella followed by oil of L. petersonii”
The same questions in other papers
botanical · crop injury · Brassica oleracea (wild cabbage)Positive and negative results
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See all 12 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.